Spitzbuben (raspberry Jam Cookies)
"All. The. Cookies. Aka: spitzbuben for everyone in the neighborhood. "
-- @sarah_fel
5 1/2 cups all purpose flour
1 3/4 cups butter, cold, cut into cubes
1 beaten egg
1 cup caster sugar
a pinch of salt
raspberry jam
Mix flour, sugar, salt.  Add the cold butter and whisk using the paddle attachment. When there are no more butter lumps, add the egg and mix until you have a smooth dough (add a teaspoon of cold water if needed t help the dough come together).
Put the dough in a plastic bag, roll it with a rolling pin until you have a 1/2 inch thick surface, close the bag and leave in the fridge for 1 hour (you can even prepare the dough the day before).
Preheat the oven to 350˚F.
Take the dough from the fridge, cut out your cookies using round cookie cutter. Leave half whole, and punch out smaller designs in the other half to go on top. Cook them for 10 to 12 minutes, they should be pale, and not brown. 
Let them cool for 5 minutes, carefully fill them with the raspberry jam and make the sandwiches.  Let them cool completely before eating.